A Lily Mills booklet explaining how to calculate yarn requirements for hand weaving. It covers yarn count systems for cotton, wool, linen, silk and rayon, yardage per pound, plied yarn notation, and worked examples for figuring warp ends, shrinkage allowance, and yarn to order for yardage and place mats and napkins, including an overshot estimate. The second half is a table of yarn count and Lily's Weaving Chart, listing Lily yarns with yards per pound and tube, colors, reed settings, and suggested uses, plus novelty yarns.